day24: part 1 solution

README.md

@@ -1,6 +1,6 @@
 <!-- AOC TILES BEGIN -->
 <h1 align="center">
-  2024 - 45 ⭐ - Rust
+  2024 - 46 ⭐ - Rust
 </h1>
 <a href="src/day1.rs">
   <img src=".aoc_tiles/tiles/2024/01.png" width="161px">
@@ -71,4 +71,7 @@
 <a href="src/day23.rs">
   <img src=".aoc_tiles/tiles/2024/23.png" width="161px">
 </a>
+<a href="src/day24.rs">
+  <img src=".aoc_tiles/tiles/2024/24.png" width="161px">
+</a>
 <!-- AOC TILES END -->

src/day24.rs

@@ -0,0 +1,229 @@
+use aoc_runner_derive::aoc;
+use itertools::Itertools;
+use nom::And;
+use regex::Regex;
+use rustc_hash::FxHashMap;
+
+#[derive(Copy, Clone, Debug)]
+enum Op {
+    And,
+    Or,
+    Xor,
+    Constant,
+}
+
+impl From<&str> for Op {
+    fn from(value: &str) -> Self {
+        match value {
+            "AND" => Self::And,
+            "OR" => Self::Or,
+            "XOR" => Self::Xor,
+            s => panic!("invalid operation {}", s),
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+struct Gate {
+    op: Op,
+    value: Option<bool>,
+    arguments: [String; 2],
+}
+
+impl Gate {
+    fn eval(&self, machine: &GateMachine) -> bool {
+        match self.op {
+            Op::And => machine.val_of(&self.arguments[0]) && machine.val_of(&self.arguments[1]),
+            Op::Or => machine.val_of(&self.arguments[0]) || machine.val_of(&self.arguments[1]),
+            Op::Xor => machine.val_of(&self.arguments[0]) ^ machine.val_of(&self.arguments[1]),
+            Op::Constant => self.value.unwrap(),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct GateMachine {
+    gates: FxHashMap<String, Gate>,
+}
+
+impl GateMachine {
+    fn val_of(&self, gate: &str) -> bool {
+        println!("gate: {}", gate);
+        if let Some(val) = self.gates[gate].value {
+            val
+        } else {
+            self.gates[gate].eval(self)
+        }
+    }
+}
+
+fn parse(input: &str) -> GateMachine {
+    let mut gates = FxHashMap::default();
+    for line in input.lines() {
+        println!("{line}");
+        let const_re = Regex::new(r"^([xyz][0-9]{2}): ([01])$").unwrap();
+        let gate_re = Regex::new(r"^([a-z0-9]{3}) (AND|XOR|OR) ([a-z0-9]{3}) -> ([a-z0-9]{3})$").unwrap();
+
+        if let Some(caps) = const_re.captures(line) {
+            println!(" is const: {:?}", caps);
+            gates.insert(
+                caps[1].to_string(),
+                Gate {
+                    op: Op::Constant,
+                    value: if &caps[2] == "1" { Some(true) } else { Some(false) },
+                    arguments: [String::new(), String::new()],
+                },
+            );
+        } else if let Some(caps) = gate_re.captures(line) {
+            println!(" is gate: {:?}", caps);
+            gates.insert(
+                caps[4].to_string(),
+                Gate {
+                    op: Op::from(&caps[2]),
+                    value: None,
+                    arguments: [caps[1].to_string(), caps[3].to_string()],
+                },
+            );
+        }
+    }
+    GateMachine { gates }
+}
+
+#[aoc(day24, part1)]
+pub fn part1(input: &str) -> i64 {
+    let machine = parse(input);
+    let z_gates = machine
+        .gates
+        .keys()
+        .filter(|k| k.starts_with('z'))
+        .map(|s| (s, s.split_at(1).1.parse::<usize>().unwrap()));
+    let bit_vals = z_gates
+        .map(|(name, bit)| if machine.val_of(name) { 1 << bit } else { 0 })
+        .fold(0, |accum, val| accum | val);
+    bit_vals
+}
+
+#[aoc(day24, part2)]
+pub fn part2(input: &str) -> i64 {
+    0
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    const EXAMPLE1: &str = "x00: 1
+x01: 1
+x02: 1
+y00: 0
+y01: 1
+y02: 0
+
+x00 AND y00 -> z00
+x01 XOR y01 -> z01x00: 1
+x01: 0
+x02: 1
+x03: 1
+x04: 0
+y00: 1
+y01: 1
+y02: 1
+y03: 1
+y04: 1
+
+ntg XOR fgs -> mjb
+y02 OR x01 -> tnw
+kwq OR kpj -> z05
+x00 OR x03 -> fst
+tgd XOR rvg -> z01
+vdt OR tnw -> bfw
+bfw AND frj -> z10
+ffh OR nrd -> bqk
+y00 AND y03 -> djm
+y03 OR y00 -> psh
+bqk OR frj -> z08
+tnw OR fst -> frj
+gnj AND tgd -> z11
+bfw XOR mjb -> z00
+x03 OR x00 -> vdt
+gnj AND wpb -> z02
+x04 AND y00 -> kjc
+djm OR pbm -> qhw
+nrd AND vdt -> hwm
+kjc AND fst -> rvg
+y04 OR y02 -> fgs
+y01 AND x02 -> pbm
+ntg OR kjc -> kwq
+psh XOR fgs -> tgd
+qhw XOR tgd -> z09
+pbm OR djm -> kpj
+x03 XOR y03 -> ffh
+x00 XOR y04 -> ntg
+bfw OR bqk -> z06
+nrd XOR fgs -> wpb
+frj XOR qhw -> z04
+bqk OR frj -> z07
+y03 OR x01 -> nrd
+hwm AND bqk -> z03
+tgd XOR rvg -> z12
+tnw OR pbm -> gnj
+x02 OR y02 -> z02";
+
+    const EXAMPLE2: &str = "x00: 1
+x01: 0
+x02: 1
+x03: 1
+x04: 0
+y00: 1
+y01: 1
+y02: 1
+y03: 1
+y04: 1
+
+ntg XOR fgs -> mjb
+y02 OR x01 -> tnw
+kwq OR kpj -> z05
+x00 OR x03 -> fst
+tgd XOR rvg -> z01
+vdt OR tnw -> bfw
+bfw AND frj -> z10
+ffh OR nrd -> bqk
+y00 AND y03 -> djm
+y03 OR y00 -> psh
+bqk OR frj -> z08
+tnw OR fst -> frj
+gnj AND tgd -> z11
+bfw XOR mjb -> z00
+x03 OR x00 -> vdt
+gnj AND wpb -> z02
+x04 AND y00 -> kjc
+djm OR pbm -> qhw
+nrd AND vdt -> hwm
+kjc AND fst -> rvg
+y04 OR y02 -> fgs
+y01 AND x02 -> pbm
+ntg OR kjc -> kwq
+psh XOR fgs -> tgd
+qhw XOR tgd -> z09
+pbm OR djm -> kpj
+x03 XOR y03 -> ffh
+x00 XOR y04 -> ntg
+bfw OR bqk -> z06
+nrd XOR fgs -> wpb
+frj XOR qhw -> z04
+bqk OR frj -> z07
+y03 OR x01 -> nrd
+hwm AND bqk -> z03
+tgd XOR rvg -> z12
+tnw OR pbm -> gnj";
+
+    #[test]
+    fn part1_example() {
+        assert_eq!(part1(EXAMPLE1), 4);
+        assert_eq!(part1(EXAMPLE2), 2024);
+    }
+
+    #[test]
+    fn part2_example() {
+        assert_eq!(part2(EXAMPLE1), 0);
+    }
+}

src/lib.rs

@@ -14,6 +14,7 @@ pub mod day20;
 pub mod day21;
 pub mod day22;
 pub mod day23;
+pub mod day24;
 pub mod day3;
 pub mod day4;
 pub mod day5;